Creating a Simple Tag

Once again, svn copy comes to the rescue. If you want to create a snapshot of /calc/trunk exactly as it looks in the HEAD revision, then make a copy of it:

$ svn copy http://svn.example.com/repos/calc/trunk \
http://svn.example.com/repos/calc/tags/release-1.0 \
-m "Tagging the 1.0 release of the 'calc' project."

Committed revision 351.

This example assumes that a /calc/tags directory already exists. (If it doesn't, see svn mkdir). After the copy completes, the new release-1.0 directory is forever a snapshot of how the project looked in the HEAD revision at the time you made the copy. Of course you might want to be more precise about exactly which revision you copy, in case somebody else may have committed changes to the project when you weren't looking. So if you know that revision 350 of /calc/trunk is exactly the snapshot you want, you can specify it by passing -r 350 to the svn copy command.

But wait a moment: isn't this tag-creation procedure the same procedure we used to create a branch? Yes, in fact, it is. In Subversion, there's no difference between a tag and a branch. Both are just ordinary directories that are created by copying. Just as with branches, the only reason a copied directory is a “tag” is because humans have decided to treat it that way: as long as nobody ever commits to the directory, it forever remains a snapshot. If people start committing to it, it becomes a branch.

Creating a Complex Tag

Sometimes you may want your “snapshot” to be more complicated than a single directory at a single revision.

For example, pretend your project is much larger than our calc example: suppose it contains a number of subdirectories and many more files. In the course of your work, you may decide that you need to create a working copy that is designed to have specific features and bug fixes. You can accomplish this by selectively backdating files or directories to particular revisions (using svn update -r liberally), or by switching files and directories to particular branches (making use of svn switch). When you're done, your working copy is a hodgepodge of repository locations from different revisions. But after testing, you know it's the precise combination of data you need.

Time to make a snapshot. Copying one URL to another won't work here. In this case, you want to make a snapshot of your exact working copy arrangement and store it in the repository. Luckily, svn copy actually has four different uses (which you can read about in Chapter 9), including the ability to copy a working-copy tree to the repository:

$ ls
my-working-copy/

$ svn copy my-working-copy http://svn.example.com/repos/calc/tags/mytag

Committed revision 352.

Svn mkdir

Create a new directory under version control.

Description:

Create a directory with a name given by the final component of the PATH or URL. A directory specified by a working copy PATH is scheduled for addition in the working copy. A directory specified by a URL is created in the repository via an immediate commit. Multiple directory URLs are committed atomically. In both cases all the intermediate directories must already exist.

Switches:

--message (-m) TEXT
--file (-F) FILE
--quiet (-q)
--username USER
--password PASS
--no-auth-cache
--non-interactive
--editor-cmd EDITOR
--encoding ENC
--force-log
--config-dir DIR

Examples:

Create a directory in your working copy:

$ svn mkdir newdir
A         newdir

Create one in the repository (instant commit, so a log message is required):

$ svn mkdir -m "Making a new dir." http://svn.red-bean.com/repos/newdir

Committed revision 26.